The producing of containers by blow forming from parisons that are made from a thermoplastic material, for example from parisons made from PET (polyethylene terephthalate), with the parisons being fed to different processing stations within a blower machine (DE-OS 43 40 291), is known. A blower machine typically exhibits a heating device for the temperature-regulating or preheating (thermal conditioning) of the parisons and a blowing apparatus with at least one blowing station within whose region the previously thermally conditioned parison is expanded biaxially or multiaxially to form a container. The expansion takes place with the aid of a compressed gas (compressed air) as pressure medium which is introduced with a shaping pressure into the parison that is to be expanded. The process sequence with such an expansion of the parison is explained in DE-OS 43 40 291.
The fundamental configuration of a blowing station is described in DE-OS 42 12 583, while possibilities of thermally conditioning the parisons are explained in DE-OS 23 52 926.
According to a typical further-processing method the containers that are produced by blow forming are fed to a downstream filling apparatus where they are filled with the product or filling substance provided. A separate blower machine and a separate filling machine are therefore used. It is also known for the separate blower machine and the separate filling machine to be combined into a machine block, i.e. into a unitized blower/filler apparatus, with the blow forming and the filling still taking place at separate machine components and in chronological sequence.
There have also already been suggestions for producing containers, in particular including in the shape of bottles, from thermally conditioned or preheated parisons and simultaneously filling them with a liquid filling substance which is fed as a hydraulic pressure medium for expanding the parison and for shaping the container with a shaping and filling pressure such that the respective parison is shaped into the container simultaneously as the filling takes place. Such methods in which a simultaneous shaping and filling of the respective container take place can also be referred to as hydraulic shaping methods or hydraulic container shaping.
When the containers are shaped from the parisons by the filling substance itself, i.e. using the filling substance as hydraulic pressure medium, then the shaping and filling of the containers requires only one machine which however exhibits an increased complexity for this purpose. However initial experimental results with such devices indicate that the quality of the produced containers is still significantly below the quality of conventionally produced blow-formed containers. One reason for this is that a large number of process parameters which are available during the execution of normal blow forming are either absent during hydraulic container forming or could not yet be developed.
A further problem with hydraulic container forming is that contamination of the respective shaping and filling station or of the mold which forms this station and which is executed similar to a blow-mold of a blow-forming machine for producing containers from thermally conditioned parisons by blowing with a pressurized gas, must be avoided. Specifically when the filling substance is totally or partially carbonated there is a significant risk of contamination of the respective shaping and filling station due to losses of the filling substance, in particular when the pressure inside the container is lowered, i.e. during the pressure let-down of the container from the very high shaping and filling pressure to ambient pressure. Such losses of filling substance are due in particular to massive foaming during pressure let-down such that it has not so far been possible to use the simultaneous shaping and filling of containers using parisons and using the filling substance as pressure medium (hydraulic forming technology), in particular for carbonated products.